This invention relates generally to radiation detectors and more particularly, to scintillators used in radiation detectors.
Due to the nature of geophysical drilling, boreholes used for geophysical logging and oil and gas production generally are circular in cross-section. Therefore, the tools used to log these boreholes are substantially cylindrical to accommodate the dimensions of the borehole. Tools used in the borehole such as for radiation surveying of the borehole, experience elevated pressures and temperatures with respect to surface ambient conditions. Due to the pressures experienced when the borehole is filled with fluid, a substantial cross-section of the tool is used to resist this pressure, leaving a relatively small amount of space available for instrumentation. It is important then that the remaining space be optimally used. Known scintillation radiation detectors used for borehole surveying are straight cylindrical or very similar objects of revolution. Such shapes, while simple to machine, waste much available shape and therefore limit the sensitivity of the entire tool. To facilitate improving detector sensitivity multiple detectors of smaller size have been used. However, such approaches require each scintillator to be coupled to photomultiplier, which greatly increases the cost of the detector.